During fabrication, present day processor integrated circuits (ICs) such as, for example, microprocessors, digital signal processors, graphics processors, and the like, are typically screened and classified into batches. The manufacturer normally sets a nominal processor clock rate based upon a statistical analysis of device behavior under different temperature conditions. The screening results in different batches of devices that run at different nominal processor clock rates. The selected nominal processor clock rate of each batch is picked so that the IC devices in the batch are operational over the worst case combinations of temperature, supply voltage, and process variation. Prescreening may also be employed prior to or as a part of mass production, by sorting each part of the fly.
In most cases, designs in which a processor IC is used operate the device far from the temperature and voltage extremes for which the part is rated. A vast majority of the processor ICs in use are capable of operating at processor clock rates far in excess of what is normally used, when operated in typical system environments (e.g., within temperature controlled business and residential premises). Processor clock rates for processor ICs may, in some instances, be raised 20% without experiencing processor operational problems. This is due to the fact that the designers of the equipment using the processor ICs limited their designs to the maximum processor clock rates published for the part by the IC manufacturer.
Operating at higher than manufacturer-specified clock rates, also known as “over-clocking” is common among some user groups, such as users of high-end personal computer game systems. Processor clock rates to be used in “over-clocking” are normally determined using imprecise trial and error methods that fail to fully and reliably realize the extent of the processor computing resource available.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.